This invention relates in general to method of assembly for a biopsy forceps jaw and a biopsy forceps jaw and more particularly to a method of assembly for a non-metallic biopsy forceps jaw and for the non-metallic biopsy forceps jaw itself used for the removal of tissue samples from a patient.
A number of different types of biopsy forceps devices have been developed for taking tissue samples. Some of the biopsy devices take the form of a forceps design with opposing jaws or radial jaws in which the jaws have intermeshing teeth. When activated, the teeth cut the desired tissue and the tissue is stored within the jaw itself. In general these devices have the majority of their design made out of metallic components. This is specifically the case for the biopsy jaw itself. In general the method of assembly for most of these devices requires meticulous effort to align and secure the metallic components of the jaw. This results in costly and time consuming assembly.
The desire to find a less costly and less complicated method of assembly has resulted in the use of some non-metallic components. Examples of prior art methods of assembly and biopsy forceps jaw devices that have been devised to address the aforenoted problems, include, U.S. Pat. No. 6,041,679 issued on Mar. 28, 2000 to Slater. This patent relates to a non-metallic end effector for use in an endoscopic surgical tool includes a metallic core for strength and for providing a selected electrode surface on the end effector. Selectively conductive end effectors are manufactured by insert molding a non-metallic or ceramic or other non-conductive body around a metallic or otherwise conductive core. More specifically, the method of manufacturing includes an end effector for an endoscopic surgical instrument having an actuation means, comprising: forming a metallic skeleton by a process chosen from casting, stamping or photochemically milling; and molding a non-conductive body around said metallic skeleton. The non-conductive body having a proximal end with means for coupling to the actuation means, and a distal end with means for cutting, gripping, clamping, or otherwise contacting tissue.
U.S. Pat. No. 5,647,115 which issued on Jul. 15, 1997, relates to a jaw assembly of an endoscopic biotome is formed by cutting a hemispherical end of a spring metal cylinder with electrical discharge or laser machining equipment to provide opposed jaw cups.
Although the prior art addresses some of the issues described above, it does not address a method of assembly for a non-metallic biopsy forceps jaw device that allows for easy assembly and the use of less costly parts.
An object of one aspect of the present invention is to provide an improved method of assembly of a non-metallic biopsy forceps jaw device and a non-metallic biopsy forceps jaw.
In accordance with one aspect of the present invention there is provided a method of assembling a biopsy forceps jaw device, comprising pivotally mounting to a single flat support having a single aperture a threaded, self-centering proximal end and a pointed distal end, an integrally connected non-metallic jaw assembly having a cutting plane. The integrally connected non-metallic jaw assembly pivots about a common axis within the single aperture allowing for rotation of the integrally connected non-metallic jaw assembly within the cutting plane. A pair of actuating wires for moving the integrally connected jaw non-metallic assembly from a closed position to an open position are attached to the integrally connected non-metallic jaw assembly. The ribbed proximal end of single flat support and the pair of actuating wires are inserted into a tubular member. The integrally connected non-metallic jaw assembly and the single flat support are centered within the tubular member through the threaded self-centering proximal end.
Conveniently, the integrally non-metallic jaw assembly may be an upper jaw and a lower jaw, wherein a cutting edge is insert molded and/or snap-connected to the lower jaw for cutting tissue. The upper and lower jaws may be snap-connected to one another.
Preferably, the threaded self-centering proximal end of the single flat support may be screwed into the tubular member thereby self-centering the jaw assembly in the tubular member.
In accordance with another aspect of the present invention there is provided a non-metallic flexible biopsy jaw assembly for a biopsy forceps device which may be inserted through an endoscope for the removal of body tissue from a body cavity, comprising a tubular member, a single flat support having a single aperture and a threaded, self-centering proximal end and a pointed distal end. The proximal end is screwed directly into the tubular member and the single flat support is self-centered within the tubular member.
An integrally connected non-metallic jaw assembly having a cutting plane is mounted pivotally about a common axis within the single aperture of the single flat support for rotation of the integrally connected jaw assembly within the cutting plane of the integrally connected jaw assembly. A pair of actuating wires are snap-connected to the integrally connected jaw assembly and are slidable relative to the tubular member and the single flat support for moving the integrally connected jaw assembly from a closed position to a open position when activated.
Advantages of the present invention include the use of non-metallic materials for the biopsy jaws thereby allowing the snap-connections of the upper and lower jaws and the actuating wires into the jaws. Furthermore, the proximal end of the single flat support is treaded in such a way that the support alone self centers the jaw assembly within the tubular member. The assembly of the device in conjunction with the components is such that it is not costly, as well as reducing the overall time required for assembly. Furthermore, the use of non-metallic components makes the device cheaper and therefore disposable if desired.